USDA Category II Animals

Question 1

Akabane Disease

Answer 1

Family: Bunyaviridae Genus: Orthobunyavirus

Transmission: Culicoides

AKA Congenital Bovine Epizootic Arthrogyposis-Hydraencephaly virus; adults asymptomatic usually; occasionally encephalomyelitis; abortions; stillbirths, congenital defects (if exposed during pregnancy)

Hosts: Cattle*, sheep, goats

Dx: Serology

Geo: Australia*, Asia, Africa

Question 2

Crimean Congo Hemorrhagic Fever

Answer 2

Family: Bunyaviridae Genus: Nairovirus

Transmission: Hyalomma ticks; Midges and Argasid ticks may be mechanical vectors. Humans

Hosts: Hedgehogs and hares seem to be reservoir. Isolated from numerous animals. Large herbivores seem to be reservoir. Asymptomatic in animals. Humans.

Sources of human exposure include being bitten by a tick, crushing an infected tick with bare skin, contacting animal blood or tissues and drinking unpasteurized milk. Exposure to blood or tissues may result in transmission.

Humans: Prehemorrhagic phase: High fever, GI symptoms, changes in mentation (aggression/confusion). Hemorrhagic phase: Petechial rash, bruises, melena, hematemesis, etc.

Dx: PCR (blood), serology

Geo: Africa, Middle East, Asia, India

Question 3

Echinococcus/hydatiosis

Answer 3

Echinoccoccus granulosus: cystic echinococcosis
Echinococcus multilocularis: alveolar echinococco
Cestodes - Taenidae- Tapeworms

Hosts: Definitive Canids (Em- cats too); Intermediate- many including humans (sheep are important in some areas)

Transmission: Ingestion of intermediate hosts (cysts) for definitive host, ingestion of proglottids (eggs) intermediate hosts

Eg- Cysts encased in capsules, Em- not encased and invasive. Signs when cysts become large and invasive. Eg- cysts in liver and lungs (most), almost anywhere though; Em- liver, metastasize to almost anywhere, more dangerous

Dx: Imaging/ serology

Geo: Worldwide; E. multilocularis - N. hemisphere

Question 4

Foot and Mouth Disease

Answer 4

Family: Picornavirus Genus: Apthovirus

Hosts: Cloven-Hoofed animals

Transmission: In all secretions and excretions, aerosol and fomite transmission including vectors.

Acute febrile illness with vesicles that erode in feet, mouth, mammary gland. Extremely painful. Possible complications include temporary or permanent decreases in milk production, hoof malformations, chronic lameness or mastitis, weight loss and loss of condition. Cattle: Mouth lesions, Pigs: Feet lesions, heart failure in young pigs.

Dx: Antigens or nucleic acid of vesicles. Serology for surveillance; cross reacts with vaccine.

Geo: North and Central America, New Zealand, Australia, Greenland, Iceland and western Europe are free of FMDV. Worldwide otherwise.

Question 5

Heartwater

Answer 5

Ehrlichia ruminantium

Hosts: cattle, sheep, goats and water buffalo

Transmission: Ambylomma ticks

Peracute disease in non-native ruminants. Acute disease: sudden fever, anorexia, listlessness, congested mucous membranes and respiratory signs, sometime diarrhea. Neurological signs often develop in affected animals; commonly reported signs include chewing movements, protrusion of the tongue, twitching of the eyelids and circling, often with a high-stepping gait progressing to convulsions and death. Subacute disease: milder signs such as a prolonged fever, coughing and mild incoordination

Dx: PCR (blood), serology.

Tx: Tetracyclines

Geo: Africa and some Caribbean Islands

Question 6

Melioidosis

Answer 6

Burkholderia pseudomallei

Hosts: Many including all common domestic species and reptiles. Humans. Goats and Sheep in Australia.

Transmission: Ingestion, via inhalation, or through wounds and abrasions (typically from environment). Direct from wound exudates, nasal secretions, milk, feces and urine.

Subclinical infections common. Symptomatic melioidosis may be acute, subacute or chronic, and mild or severe. Acute usually septicemia. Respiratory disease, near disease, nonspecific illness common. Depends on site of abscesses. Humans: same as animals, skin lesion, parotid abscesses

Dx: Culture

Tx: Intrinsic resistance to many abx, relapses common, euthanasia usually recommended.

Geo: Many cases in Asia and Australia but reported worldwide. Sporadic in US.

Question 7

Japanese Encephalitis Virus

Answer 7

Flavivirus

Transmission: Culex Mosquitoes

Hosts: Humans and horses (incidental), herons, egrets and pigs amplifying hosts

Horses: Similar disease as WNV. Pigs: Abortions/stillbirths, asymptomatic or transient febrile illness. Humans: nonspecific, GI, neurologic signs -encephalitis and meningitis

Dx: Serology or virus isolation

Pig and Horse vaccine in endemic areas, human vaccines too

Geo: Asia, western pacific

Question 8

Screwworm Myiasis

Answer 8

Cochliomyia hominivorax (New World) Western Hemisphere

Chrysomya bezziana (Old World) Eastern Hemisphere

Transmission: eggs are laid on edge of wound, larvae feed on healthy tissue, enlarging wound

Hosts: all mammals
(rare in birds)

Any open wound including dehorning wounds, navels, tick bites, can enter through mucous membranes; often tunnel under skin; serosanguineous discharge common; secondary infection common

Flies are larger than housefly, New world is metallic; larvae resemble a screw

Control: Sterile male release

Question 9

Rift Valley Fever

Answer 9

Bunyavirus (fam); Phlebovirus (gen)

Hosts: Ruminants, monkeys, rodents, lab animals, newborn pups/kittens; Sheep, goats, cattle primary amplifying hosts; humans

Transmission: Culex, Aedes, Anopholes mosquitoes; Survives in dry periods in Aedes eggs; In Utero in ruminants and camels; Humans- direct contact with infected tissues, contact with aerosolized virus in labs/slaughter, and mosquitoes

Geo: Subsaharan Africa

High mortality in newborns and abortions common. Nonspecific fever, hemorrhagic diarrhea, abdominal pain. Icterus more likely in calves (vs lambs). Abortion storms. Hepatic necrosis common. Humans- most asymptomatic or mild, flu-like illness, vomiting/diarrhea, photophobia, arthralgia, retinal lesions. Hemorrhagic syndrome (<1%), Encephalitis (<1%), Renal dysfunction.

Dx: PCR, ELISA antigen tests,

Vaccine available for ruminants

Epidemics after heavy rainfall; sheep have higher abortion rates than other ruminants

Question 10

Rinderpest

Answer 10

Paramyxoviridae (fam), Morbillivirus

Eradicated 2011 through vaccination campaigns.

Cattle and Buffalo*, outbreaks can be 100% fatal. Other cloven-hooved animals.

Transmission: direct or close contact with infected animals; virus found in nasal, eye secretions, and feces.

Acute high fever; reddened gums and eyes with cloudy eyes, nasal discharge, and oral sores, followed by watery/bloody diarrhea.

Dx: viral antigen detection or RNA (PCR)

Question 11

Surra

Answer 11

Trypanosoma evansi

Hosts: Most domesticated animals. Camels in ME and Africa; Horses in South America; SE Asia- horses, cattle, and buffalo. Capybara and Vampire Bats are both reservoir hosts and vectors.

Mechanical transmission by biting flies, vampire bats in S. America

Subacute, acute, or chronic. Impacts horses most. Fever, mucous membrane petechiae, extravasation of blood at mucocutaneous junctions. Wasting. Exudation, alopecia, necrosis, ulceration on coronary bands. Edema. Fatal within 2-4 months, mortality high in horses, dogs, and cats. Dogs- acute and fatal. Dogs may have rabies-like signs.

Dx: Blood, lymph node, skin, liver, kidney exudates. Thick and thin blood smears.

Question 12

Trypanosomiasis

Answer 12

T. congolense, T. vivax, T. brucei.

Hosts: Livestock

Transmission: TseTse (Glossina spp) Flies, subSaharan Africa. T. vivax in S. and Central America; vector unknown.

Chronic infection in cattle- anemia, fever, edema, weight loss. May cause immunosuppression. Infertility and abortion can be seen. Indigenous species more resistant, high fatality rate.

Dx: Thick or thin blood smears

Question 13

Vesicular Stomatitis

Answer 13

Rhabdoviridae (fam), Vesiculovirus (genus)

Hosts: Horses, donkeys, mules, cattle, swine, alpaca/llama. Sheep/goats relatively resistant.

Endemic in Americas, outbreaks in US.

Poorly understood transmission. Sandflies, and black flies possible. Can spread animal-animal contact, or via fomites contaminated with saliva or fluid from vesicles. Humans- same ways, plus aerosol in labs.

Characteristic blanched, raised vesicles (blisters) found on lips, nostrils, hooves, or teats, and in the mouth. Vesicles vary in size. Vesicles eventually rupture, leaving painful erosions and anorexia. Humans- influenza like illness with rare vesicles.

Dx: Viral antigen or PCR on vesicle fluid.

Question 14

Bovine Babesiosis

Answer 14

Babesia bovis (more virulent) and B. bigemina

Hosts: cattle, water buffalo, African buffalo

Eradicated in US in 1943

Geo: Asia, Africa, C. and S. America, Southern Europe, and Australia

Transmission: Rhipicephalus (Boophilus) microplus. Mechanical vectors: biting flies, fomites

More common in older animals; anorexia, high fever, animals may separate from herd, rough coat, injected MM, anemia. Sequestration in brain capillaries may lead to incoordination, teeth grinding, mania.

Dx: Blood smears, Serology

Question 15

Bovine Ephemeral Fever

Answer 15

Rhabdovirus (Fam) Ephemerovirus

Hosts: Cattle

Geo: Africa, Australia, and Asia, India

Transmission: Mosquitoes and culicoides

Biphasic or triphasic fever. Drastic decreased milk production. Tachycardia, tachypnea, depression, anorexia, ruminal atony, stiffness, shifting lameness. Recumbancy, muscle twitching, temporary paralysis. Abortion. Fibrin rich fluid in body cavities.

Question 16

Contagious Bovine Pleuropneumonia

Answer 16

Mycoplasma mycoides mycoides small colony type

Eradicated from US in 1893

Geo: Africa, ME, and Asia

Transmission: Close contact (inhalation of infected droplets from coughing). Intro of carrier animal into infected herd most common way.

Fever, cough, thoracic pain, dyspnea, tachypnea. Polyarthritis. Unilateral pneumonia.

Dx: PCR, Sero tests.

Question 17

Hemorrhagic Septicemia (Cattle)

Answer 17

Pasteurella multocida, serotypes B:2 (All endemic areas) and E:2 (Africa)

Cattle and buffalo (water buffalo most affected)

Geo: Asia, Africa, southern Europe, ME

Transmission: Direct contact, fomite transmission; ingestion or inhalation; Carriers important in transmission

Acute or peracute disease; Fever, reluctance to move. Salivation and serous nasal discharge, edematous swellings in pharyngeal region. Respiratory distress. Very high mortality.

Dx: Culture

Question 18

Lumpy Skin Disease

Answer 18

Poxvirus (family), Capripoxvirus (genus)

Hosts: Cattle, zebus, domestic buffalo

Geo: Africa

Transmission: Mosquitoes and flies

Inapparent to severe disease, fever followed by skin nodules of varying size. Nodules become necrotic; called ‘sit-fasts’, painful. Depression, anorexia, excessive salivation. Nodules can develop almost anywhere, including GI tract. Mortality usually low, can be high.

Dx: Virus isolation

Question 19

Theileriosis (East Coast Fever)

Answer 19

Theileria parva

Hosts: Cattle and Buffalo

Geo: S. Sudan to South Africa

Transmission: Rhipicephalus appendiculatus, other Rhipicephalus spp. No transovarial transmission.

Generalized lymphadenopathy, fever, anorexia, rapid loss of condition. Lacrimation, nasal discharge, corneal opacity, tachypnea. Terminally: pulmonary edema, dyspnea, frothy nasal discharge. “Turning Sickness”- blocking of capillaries in CNS. Recovered animals often are asymptomatic carriers. Hepatosplenomegaly, widespread hemorrhage and petechiae on necropsy. Mortality up to 100% in non-native animals.

Dx: blood smears, PCR, ELISA

Question 20

Contagious agalactia

Answer 20

Mycoplasma agalactiae

Hosts: Sheep and goats, goats particularly susceptible

Geo: Former Soviet Union, India, Pakistan, Near East, Mediterranean region

Transmission: Organism shed in urine, feces, and milk. Asymptomatic or chronic carriers important- can be shed in more than one lactation. Ingestion of contaminated milk primary transmission. Ingestion of bodily fluids or inhalation also possible.

Asymptomatic, mild, acute, or chronic. Fever, inappetence, mastitis (hot and swollen udder). Milk is off color, watery at first, then lumpy. Lactation diminishes or completely stops. Polyarthritis common. Abortions possible. Most cases develop soon after parturition.

Dx: Isolation of organism, PCR, serology

Question 21

Contagious caprine pleuropneumonia

Answer 21

Mycoplasma capricolum capripneumonia

Hosts: goats

Geo: Africa, ME, Eastern Europe, Former soviet union, Far East.

Transmission: inhalation of infected respiratory droplets.

Distinct respiratory disease. Fever, anorexia, labored respiration, coughing. Acute cases have high fatality (70-100%), chronic cases can occur upon reexposure.

Dx: Isolation of organism. PCR.

Question 22

Maedi-visna (Ovine progressive pneumonia)

Answer 22

Retrovirus (family), lentivirus (genus)

Hosts: Sheep (primary) and goats

Geo: Widespread, found in US

Transmission: Consumption of colostrum or milk. Asymptomatic carriers common.

Dyspnea (maedi), progressive neurologic disease (visna), arthritis, mastitis. Most animals asymptomatic. Maedi- wasting, progressive dyspnea, dry cough, secondary bacterial infection. Visna- more rare form, hindlimb weakness and loss of condition progressing to paresis and paralysis. Also slowly progressive arthritis. Disease usually fatal once clinical signs appear.

Dx: Serology and Histology, PCR

Question 23

Nairobi sheep diseases

Answer 23

Bunyavirus (family); genus Nairovirus

Hosts: Sheep and goats

Geo: East Africa

Transmission: Mainly Rhipicephalus appendiculatus, maintained by TO passage. Mechanical transmission can occur experimentally, not in nature.

Acute hemorrhagic gastorenteritis. Very high fever, depression, diarrhea. Bloody and mucous laden stools. Bloodstained mucopurulent discharge. Abortions common. Mortality high in non-native animals.

Dx: Serology

Question 24

Peste des petits ruminants

Answer 24

Paramyxovirus, morbillivirus (genus)
Very similar to rinderpest.

Hosts: Goats and Sheep

Geo: Africa, ME, India

Transmission: Inhalation of aerosols from sneezing and coughing animals. Virus present in nasal, ocular, and oral secretions as well as feces.

Acute illness with sudden fever. Serous nasal discharge that becomes purulent. Crusting can be severe. Necrosis of nasal mucous membranes. Necrotic stomatitis. Abortion. Bronchopneumonia. Peracute form with high mortality seen in goats. Inflammation and necrotic lesions throughout GI tract. Mortality 50-100%.

Dx: PCR, Serology

Question 25

Sheep Pox and Goat Pox

Answer 25

Poxviridae, genus Capripoxvirus
Same as Lumpy Skin Disease

Hosts: Sheep and goats

Geo: Nothern Africa, ME, China, India

Transmission: aerosol after close contact with severely affected animals containing ulcerated papules on the mucous membranes. Fomite transmission also. Virus found in milk, saliva, scabs.

Mortality 100% in non-native animals. Papules and macules progress to ulcerated lesions with necrotic centers. Lesions in GI and Respiratory tract too.

PCR, antigen detection ELISA

Question 26

African Horse Sickness

Answer 26

Reovirus, genus Orbivirus

Hosts: Equids and camels

Geo: Subsaharan Africa

Transmission: Culicoides

Peracute/pulmonary form: fever, severe respiratory distress, death in a few hours

Subacute edematous/cardiac form: fever, edematous swellings in supraorbital fossae and eyelids* (characteristic of dz), spread to face in into neck and chest. No edema of lower legs.

Acute or mixed form: Both pulmonary and cardiac forms seen.

Horsesickness fever form: mild fever, anorexia, rarely fatal.

Overall mortality in horses 50-95%, rare death in african donkeys and zebra.

Dx: Isolating virus, PCR, antigen tests

Monovalent vaccine in endemic countries.

Question 27

Contagious Equine Metritis

Answer 27

Taylorella equigenitalis

Eradicated from US, reported in UK and Europe

Hosts: Horses

Transmission: Venereal; Mechanical vectors and AI also

Stallions are asymptomatic carriers. Infected mares develop acute purulent metritis and temporary infertility, although they can be asymptomatic. Foals born to infected mares can become lifelong asymptomatic carriers. Morbidity is high, mortality is low.

Dx: culture, PCR

Question 28

Dourine

Answer 28

Trypanosoma equiperdum

Geo: Asia, Africa, South America, and SE Europe

Hosts: Equids

Transmission: Venereal. Organism found in the vaginal secretions and seminal fluid. Intermittent noninfectious periods.

Genital swelling (edema), cutaneous plaques, and nervous signs. Clinical signs wax and wane. Mares can have mucopurulent vaginal discharge. Abortion. Nervous signs a chronic sequelae. 50-100% fatal.

Dx: Serology, ID of organism

Question 29

Epizootic Lymphangitis

Answer 29

Histoplasma capsulatum var. farciminosum

Geo: ME, India, Far East, Africa

Hosts: Equids

Transmission: Soil saprophyte that infects open wounds. Can be spread on grooming equipment. Flies may also transmit.

Painless nodule enlarges then bursts, becoming an ulcer. Cycles of granulation, healing, and eruption. Spread via lymphatics, causing cord-like thickening of lymphatic vessels. Occasionally arthritis, conjunctivitis, or serous/purulent nasal discharge and pneumonia can be seen. Low mortality.

Dx: ID of organism on smear or histopath. Culture.

Question 30

Equine Piroplasmosis

Answer 30

Babesia equi and Babesia caballi

Geo: Eradicated from most developed countries, otherwise worldwide

Hosts: Equids

Transmission: B. equi Dermacentor, Hyalomma, and Rhipicephalus ticks. Horses needed for maintenance. B. caballi same ticks but is passaged TO. Contaminated needles and syringes.

Variable and non-specific clinical signs. Fever, inappetence, labored breathing, congestion of mucous membranes. Anemia, jaundice, hemoglo binemia, petechial hemorrhages on conjunctiva. Subacute cases may have intermittent fever, weight loss, mild colic. Foals infected in utero are weak and rapidly develop anemia and jaundice.

Dx: Blood smears, serology, PCR

Question 31

Glanders

Answer 31

Burkholderia mallei

zoonotic; nodules with hematogenous spread of organism.

Geo: Eradicated from many developed countries

Transmission: ingestion of nasal secretions; sharing water and feed troughs, nuzzling

Hosts: Horses and Mules

Nasal, cutaneous, or pulmonary clinical signs. Nasal- yellow-green discharge with nodules and ulcers on the nasal mucosa. Regional lymph nodes enlarge and rupture. Cutaneous form (farcy)- nodules and ulcers on skin and exude a yellow discharge. Cutaneous lymphatic vessels fill with pus forming firm ‘farcy pipes’. Pulmonary form- dyspnea and coughing, infectious nodules founding the lungs. Nodules can also be found in the liver, spleen, or testes. Acute infections are seen more often in donkeys and mules and can be highly fatal.

Dx: Smears from fresh exudates (gram negative), serology. Mallein test.

Question 32

Hendra Virus

Answer 32

Paramyxoviridae; henipavirus (genus)

Geo: Australia

Hosts: Natural infections in horses and humans. Fruit bats are asymptomatic carriers. Cats are experimentally infected.

Transmission: Close contact. Ingesting the virus in contaminated feed or inhalation. Infected bat urine or aborted bat fetuses may spread infection to horses.

Fever, anorexia, sweating, ataxia, uneasiness. Labored breathing, mild neurologic signs, subcutaneous edema. Copious frothy nasal discharge. Acute death (1-3 days). Cats- fever and tachypnea followed by rapid death.

Dx: Virus isolation, detection of nucleic acid or antigens, serology.

Question 33

Venezualan Equine Encephalomyeltis

Answer 33

Togaviridae, genus (alphavirus)
Epidemic and enzootic types

Hosts: Epidemic types- horses and humans. Enzootic maintained in wild rodents (reservoir)

Geo: Latin America

Transmission: Epidemic types are amplified in horses and transmitted by Aedes, Anopholes, Culex, and others.. Endemic types: culex mosquitoes.

Febrile prodrome followed by neurologic signs, some permanent in recovered animals. High mortality. Humans: encephalomyelitis and adverse fetal outcomes if infected during pregnancy.

Dx: Serology

Vaccination and movement control.

Question 34

African Swine Fever

Answer 34

Asfaviridae
Double stranded DNA Virus (unique)

Geo: SubSaharan Africa, former USSR

Transmission: Ornithodoros moubata (soft tick), direct contact with infected animals (oronasal), indirect on fomites. Ingestion of infected meat. Particularly high virus in blood. Environmental persistence.

Hosts: Maintained in ticks and warthogs. Symptomatic in domestic and feral pigs.

High fever and skin reddening (hyperemia). Cyanotic skin blotching. Hemorrhagic disease (probably inhibition of blood clotting). Diarrhea and abortions. Death rate varies depending on strain.

Dx: Virus isolation or serology

Question 35

Classical Swine Fever

Answer 35

AKA Hog Cholera, clinically indistinguishable from ASF
Flaviviridae, genus Pestivirus

Geo: Eradicated from US, Canada, NZ, Australia, and most of Western Europe. Endemic elsewhere.

Transmission: Oral, often spread by feeding garbage. Infections through MM and skin abrasions too. Large droplet respiratory spread. Vertical (piglets will be persistently infected). Fomite.

Hosts: Pigs only

Fever, anorexia, constipation followed by diarrhea. Hyperemia and seizures. Chronic infections can have stunted growth. Acute disease highly fatal. Abortion and perinatal death common. Congenital abnormalities. Hemorrhagic disease.

Dx: Antigen detection and serology

Vaccination

Question 36

Menangle Virus Infection

Answer 36

Paramyxoviridae, genus (Rubulavirus)

Geo: Australia (single outbreak 1997)

Hosts: virus circulates among flying foxes. Pigs. Humans.

Transmission: 2 human cases were closely associated with infected pigs (necropsy and birthing piglets). Fecal oral or urine- oral suspected.

Fever, inapparent. Sows infected in gestation had mummified fetuses, autolysed and fresh stillborn piglets, and a few normal live piglets. Congenital defects common.

Dx: serology.

Question 37

Nipah Virus Infection

Answer 37

Paramyxoviridae, Henipavirus.

Geo: Malaysia, Singapore, Bangladesh, India.

Transmission: Close direct contact with excretions or secretions of infected pigs. Human-human suspected in outbreak in Bangladesh. Bat transmission unclear (urine suspected).

Hosts: Fruit bats, domestic animals (goats, dogs, cats, and horses), pigs. Humans.

In pigs and humans: Respiratory disease. Neurological signs.
In horses: Neurologic disease or sudden death.

Dx: Viral isolation, serology

Question 38

Reston Ebolavirus Infection

Answer 38

Filoviridae, Ebolavirus

Geo: Philipines

Outbreak in the Philipines in 2008.

Transmission: Probably close contact, handling during slaughter, food chain.

Hosts: Non-human primates. Pigs. Humans

Hemorrhagic fever. Considered low pathogenicity in humans.

Question 39

Swine Vesicular Disease

Answer 39

Picornaviridae, enterovirus
Antigenically identical to human Cocksackie B-5

Geo: Asia and East Europe.

Transmission: Direct contact or fecal contact, feeding of meat scraps. Ruptured vesicles.

Hosts: Swine Only. Humans in lab setting.

Indistinguishable from FMD. Morbidity lower, lesions less severe. Vesicles and erosions on snout, mammary glands, coronary band, and interdigital areas.

Dx: ELISA, Virus isolation

Question 40

Teschovirus encephalomyeltis

Answer 40

Picornaviridae, teschovirus (genus)

Geo: Eastern Europe and Madagascar

Transmission: Direct or indirect contact with infected pigs.

Hosts: Pigs

Inapparent; Ataxia, fever, seizures, nystagmus, opisthotonos, and como may occur. Paralysis may occur.

Live attenuated vaccine in endemic areas.

Dx: Acute and convalescent serum titers.

Question 41

Vesicular Exanthema

Answer 41

Calicivirus, genus vesivirus
lots of related viruses, including San Miguel sea lion virus.

Geo: Last seen in US in 1959.

Acute, highly infectious disease. Fever, vesicles on snout, oral mucosa, soles of feet, coronary band, between toes. Indistinguishable from FMD, Vesicular stomatitis, and swine vesicular disease.

Question 42

Duck Virus Hepatitis

Answer 42

Alphaherpesvirinae, Mardivirus

Geo: Europe, Asia, and North America

Transmission: Contaminated water.

Hosts: Ducks, Geese, Swans are natural reservoir.

Acute, highly contagious disease of ducks, geese, and swans of all ages. Severe vascular damage (hemorrhages and petechial lesions). Secondary infections common. High mortality.

Vaccine available.

Dx. PCR

Question 43

Fowl Typhoid and Pullorum Disease

Answer 43

Salmonella Gallinarum and Salmonella Pullorum

Incidence low in USA, Canada, Europe (SG). SP eradicated from US.

Transmission: Egg-transmitted Salmonella, or direct/indirect contact with infected feces.

Hosts: Chickens and Turkeys

High fatality in young chickens/turkeys. (first few weeks). Huddled near heat source. Unabsorbed yolk sacs and gray nodules in internal organs.

Dx: Isolation, ID, and serotyping.Serologic tests.

No vaccine in USA, Other countries have vaccines for S. Gallinarum

Question 44

Newcastle Disease (velogenic)

Answer 44

Paramyxoviridae, genus (Rubulavirus)

Geo: Worldwide, some countries in Europe and US free of disease, although outbreaks in wild birds are seen.

Hosts: Many avian species. Chickens most susceptible, duck and geese least.

Transmission: Direct contact with feces and respiratory discharges, or by contamination of environment. Environmental persistence, especially in feces.

Velogenic pathotype has high mortality rates, respiratory and neurologic signs or hemorrhagic intestinal lesions. Initial drop in egg production followed by numerous deaths. Surviving birds may have permanent neuro deficits and decreased egg production. May see edema and hemorrhages on head/facial tissue. Dyspnea common.

Question 45

Myxomatosis

Answer 45

Poxvirus

Geo: Worldwide, USA coasts of CA and OR (overlap with California brush rabbit, a reservoir)

Transmission: mosquitoes, fleas, biting flies, and direct contact

‘Big head’, mucinous skin lesions or myxedema; Fibroma-like lesions in cottontail; conjunctivitis progressing to milky ocular discharge. Acute death. Facial /ear edema. Purulent nasal discharge. Swollen genitalia.

Hosts: Cottontail and Jackrabbits resistant, but fatal in all breeds of domesticated rabbits.

No vaccine in USA. Euthanasia recommended.

Question 46

Rabbit hemorrhagic disease

Answer 46

AKA: Rabbit calicivirus, genus Lagovirus

Geo: endemic in Australia, NZ, Cuba, parts of Asia and Africa, and most of Europe.

Hosts: wild and domesticated European rabbits (O. cuniculus)

Transmission: direct contact with live or dead animals, fomites; long term survival in dead carcasses and shedding after recovered

Young animals- subclinical. Peracute and acute disease in older rabbits, terminal squeals followed rapidly by collapse and death. Nonspecific in many, anorexia. Neurologic in some- convulsions and mania. Respiratory signs. Mortality can approach 100%.

Dx: Viral nucleic acids and or antigens in tissues.

Question 47

Epizootic hematopoietic necrosis

Answer 47

Family: Iridovirus, genus Ranavirus

Geo: Australia

Hosts: Redfin perch and rainbow trout.

Perch- sudden death. Hemorrhages in gills and base of fins. Trout- skin ulcers and loss of equilibrium. Morbidity and mortality especially high in perch. Necrosis in renal tissue.

Transmission through water.

Question 48

Epizootic ulcerative syndrome

Answer 48

Aphanomyces invadens (fungus, water mould)

Hosts: Wild and farmed freshwater fish. Juvenile and young adults only.

Transmission through water.

Necrotizing ulcerative lesions, leading to granulomatous response. Red spot disease.

Question 49

Gyrodactylosis

Answer 49

Gyrodactylus salaris
(ectoparasite in Atlantic salmon)

Geo: Europe/Russia

Transmission: transport/restocking of live fish. Water transmission (fresh and brackish water)

Commonly found on body and less so on gills. Causes skin wounds that can be large.

Question 50

Louping Ill

Answer 50

Family Flaviviridae, genus Flavivirus

Geo: Scotland, Ireland, Wales

Hosts: Sheep, dogs, cattle, horses

Transmission: Ticks (Rhipicephalus, Ixodes, Haemaphysalis). I. ricinus thought to be natural vector.

Fever, depression, anorexia in sheep. Second fever spike correlates with CNS invasion of virus: incoordination, ataxia, hyperesthesia, profuse salivation, tongue protrusion, champing of the jaws, and characteristic ‘looping’ gait. Death common.

Question 51

Monkeypox

Answer 51

Family: Poxviridae Genus: Orthopoxvirus (DNA virus)

Geo: DRC, endemic in Central and West Africa

Hosts: many, but monkeys/apes, rodents, humans.

Transmission: Bites, aerosols, skin abrasions, or infected tissue.

Nonhuman primates and humans: Fever, nonproductive cough, and vesicular and pustular rash (pocks). Red, necrotic, depressed center. Fatalities in infants. Rodents: Fever, lymphadenopathy, cough, and pustules or pathcy alopecia.

Fatality 1-10% in Africa. Smallpox vaccine may decrease severity.